In order to form tubular wrappings, several strips of paper, aluminium and others are helically rolled, the number of these strips depending on the thickness of the wall of said wrapping. However it is necessary to cover said strips with adhesive. According to the nature of the material forming the strip and/or the thickness thereof it is necessary to modify the thickness of the film of adhesive. Frequently, it is necessary to modify this thickness during the operation of the machine forming tubular wrappings and, for this reason, this change must be able to be effected simply and rapidly.